Metal pumping and siphoning



May 15, 1951 M, TAMA 2,552,876

METAL PUMPING AND SIPHONING Filed Feb. 4, 1947 I NVEN TOR: j /W10 ii/kWh Patented May 15, 1951 METAL PUMPING AND SIPHONING Mario Tama,Morrisville, Pa., assignor to Ajax Engineering Corporation, Trenton, N.J.

Application February 4, 1947, Serial No. 726,349

1 Claim. 1

This invention is a continuation in part of my copending patentapplication Serial No. 647,831, filed February 15, 1946, which hasmatured into Patent No. 2,536,325 dated January 2, 1951; the inventionrelates to a method and means of transporting molten metals from aninduction furnace into a ladle or similar type of container.

In conformity with my prior invention the molten metals are pumped froman induction furnace through the sole expedient of electromagneticforces which are created in the metal bath by a current flowing in adirection parallel to the discharge direction of the molten metal.

This molten metal transporting scheme which necessitates the constantsupply of a comparatively high voltage current serves its purposes wellin all those cases where the metal flow requires frequent interruptions;this situation applies, for instance, to the direct mold-casting fromthe furnace or to the discharge of smaller fractions of the molten metalcharge; it involves as above indicated the continuous supply of a highvoltage current with its resulting costs.

It is the main object of this invention to modify and to economize themolten metal transporting method of Patent No. 2,536,325 by restrictingthe current expenditure to a fraction of the time required for emptyingthe charge from the furnace.

It is a further object of the invention to initiate the metal flow fromthe furnace by the use of electromagnetic forces induced by high voltagecurrent in the metal bath,'but to continue and complete the metaloutflow from the furnace without the incurrence of, this rather costlyoperating source.

It is also an object of the invention to produce a calmer outflow of themolten metal from the furnace by the elimination of eddy currents andsimilar disturbances which are an unavoidable consequence of inducedelectromagnetic forces of high voltage.

With these and other objects in view, which will become apparent as'thisspecification proceeds, the invention consists of a method for thecontinuous transport of the entire molten metal charge or of asubstantial part thereof from an induction furnace of the submergedresistor type into a container, for instance a ladle; this methodcomprises passing by electromagnetic induction a current through a lowersection of the metal bath contained in this furnace, superimposing inthe lower section of the metal bath an induced electromagnetic pressureupon its hydrostatic pressure, creating thereby in the lower bathsection a zone of a higher liquid pressure than this hydrostaticpressure, placing the one end of a tube of an electrically conductiverefractory material in the zone of the high liquid pressure and theother end of this tube outside of the metal bath at a lower level thanthe first tube end, creating by the said higher liquid pressure a flowof the molten metal from the furnace through the tube and thereuponsyphoning the molten metal from the furnace by the level difference atthe tube ends.

The invention is illustrated by way of example in the attached drawings.

Fig. 1 is a vertical sectional elevation of sub merged resistor typeinduction furnace equipped for the performance of the invention,

Fig. 2 is a vertical sectional elevation on line 2-2 of Fig. 1.

The furnace shown in Figs. 1 and 2 is similar to the furnace disclosedin my copending application Ser. No. 647,831.

The furnace contains an upper receptacle or hearth 1 for the moltenmetal, a secondary melt ing loop located underneath this hearth andlower inductor unit consisting of two secondary blocks all encased by anouter housing 3 lined with a suitable refractory 4.

The secondary loop system consists of three vertical channels l5, l6,[1, a bottom channel I8 connecting their lower ends and a bottom groove16 provided in the hearth.

A transformer assembly consisting of the primary copper coils 19, 20 andthe laminated iron core l3 which is closed in itself is provided in thecustomary manner.

A U-shaped tube 2| made of a suitable electrically conductive refractorymaterial such as, for instance, graphite is inserted into the meltingchannel H with its one branch or section 21a into center channel I! ofthe secondary loop; this tube branch Zla extends vertically upwardsthrough the molten metal charge 12, is then bent into a horizontalsection 2lb which leads from the furnace and finally into a downwardlyextending section 210. This latter section ends at a level which issituated below the end of tube section 2 la.

A ladle II adapted to accommodate the entire metal charge of the furnaceis located underneath the end of tube section Zlc.

The operation of the furnace for the purpose of this invention will nowbe described.

The hearth is filled with the molten metal l2. A high voltage current isgenerated by induction within the secondary loop. Due to the highelectromagnetic pressure created in the channel ll which pressure issuperimposed on the hydrostatic pressure of the molten metal, the latteris forced into the lower end of tube sections 2111 and flows upward intotube section 2 lb and from there through tube section 2Ic into ladle H.

The current supply is maintained until a steady flow of the molten metalis secured through the tube into the ladle; then the current isinterrupted and the discharge of the metal is completed by a syphoningaction only caused in the usual manner by the level and pressuredifierence at the two ends of tube sections 2m and Zlc.

The generally known liquid syphoning principle is here combined with theelectromagnetic pumping method of Patent No. 2,536,325 dated January 2,1951, and applied in a highly efficient and economical manner to thetransport of molten metal from an induction furnace into a ladle for thepurpose of emptying the charge in a continuous manner into the latterand greatly reducing the costs of the metal discharge.

I claim:

An electromagnetic induction pump for molten metals comprising areceptacle to hold a molten metal bath and a secondary melting loopbeneath said receptacle, the said melting loop consisting of a bottomchannel spaced from said receptacle and melting channels connectingsaid. bottom channel and said receptacle, a transformer assembly toinduce current in said .secondary melting loop and to superimpose in thesame an electromagnetic pressure upon the hydraulic pressure of themolten metal, a U-shaped refractory tube reaching with the end of itsfirst branch into the upper end of a melting channel, leading upwardlyinto a location of reduced pressure, sothat a unidirectional fiow takesplace to start the siphoning action from said receptacle and reachingdownwardly with the end of the second branch to a point locatedunderneath the end of said first branch.

MARIO TAMA.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,660,407 Bainbridge Feb. 28,1928 1,944,733 Doerschuk Jan. 23, 1934 1,983,579 Ennor Dec. 11, 19341,983,580 Nook Dec. 11, 1934 2,083,022 Hoke June 8, 1937 2,224,982 MorinDec. 17, 1940 2,386,369 Thompson Oct. 9, 1945 2,397,785 Friedlander Apr.2, 1946 2,536,325 Tama Jan. 2, 1951 FOREIGN PATENTS Number Country Date126,947 Great Britain Dec. 24, 1919

